Every year, a staggering 100 million citizens of the European Union travel, live or work in a member state other than their own. This opportunity for the free movement of people is one of the principle benefits that membership of the EU has brought to all of us – and one that is widely recognised.

What is less widely recognised is that this free movement of peoples is supported by a number of measures designed to make our lives easier and safer. For instance, did you know that it’s possible to dial the emergency services anywhere in the EU by using a single number? The number is 112.

If you dial 112 in the UK, you get patched through to the emergency services exactly as if you had dialled 999. In other countries, you get similar assistance from the country’s own emergency services. No national numbers are being replaced – 999 and other national numbers will continue to work as normal – but the extra number guarantees that you don’t need to memorise 25 different numbers for the 25 countries of the EU. It makes sense.

So why choose 112? The answer is simple. 999 was originally selected as a number in the days of old-style telephones with circular dials. To dial 9, you simply turned the dial all the way around until it stopped – which made it much easier to dial in the dark than any other number. These days, modern touch-tone phones make it much more difficult to locate the 9 key in the dark, but it is very easy to find the upper left-hand corner of the keypad – the digit 1. So the number selected for the emergency services was 112.

The website of the European Emergency Number Association is here.